Artificial intelligence (AI for short) is a new technology for studying and developing theories, methods, technologies and application systems for simulating, extending and expanding human intelligence. AI is a branch of computer science, intending to know essence of intelligence and to produce an intelligent machine able to act in a way similar to that of human intelligence. Researches on the AI field refer to robots, speech recognition, image recognition, natural language processing and expert systems etc. A significant branch of AI is the speech recognition technology.